Final answer:
The correct sentence using proper punctuation is option c) 'Listening to her stereo and reading love stories are my sister's chief pleasures.' It uses an apostrophe to show possession and has no unnecessary commas.
Step-by-step explanation:
The correct sentence that uses correct punctuation is: c. Listening to her stereo and reading love stories are my sister's chief pleasures. This sentence is properly punctuated with an apostrophe in "sister's" to show possession and lacks unnecessary commas.
In sentence a, there's an incorrectly placed comma after "stereo," which is not necessary because "and" already connects the two activities that are the subject of the sentence. Sentence b is missing the possessive apostrophe in "sisters".
Regarding subject-verb agreement, while the subject "Listening to her stereo and reading love stories" is a compound subject because it is two activities connected by "and," it is considered a singular idea reflecting the sister’s hobbies. Hence, the verb should technically be singular ('is' instead of 'are'), but this detail is not part of the question's focus.